Ligature (Medicine)

A ligature is a piece of thread or suture tied around an anatomical structure, most often a blood vessel, to shut it off. During surgery a vessel is typically clamped with a hemostat, tied off with suture material, then divided, a technique that differs from a tourniquet because the knot is permanent rather than adjustable. The same principle is used outside major surgery to remove skin tags, by tying a thread or band around the base to cut off its blood supply until the tissue separates. The practice dates back to Hippocrates and Galen, was used by Roman surgeons for hemorrhoids, was described by the physician Al-Zahrawi around 1000 CE, and became standard surgical practice through Ambroise Pare and Jules-Emile Pean in the nineteenth century.